Textination Newsline

• For sports and physiotherapy alike

Researchers at ETH Zurich, Empa and EPFL are developing a 3D-printed insole with integrated sensors that allows the pressure of the sole to be measured in the shoe and thus during any activity. This helps athletes or patients to determine performance and therapy progress.

In elite sports, fractions of a second sometimes make the difference between victory and defeat. To optimize their performance, athletes use custom-made insoles. But people with musculoskeletal pain also turn to insoles to combat their discomfort.

Before specialists can accurately fit such insoles, they must first create a pressure profile of the feet. To this end, athletes or patients have to walk barefoot over pressure-sensitive mats, where they leave their individual footprints. Based on this pressure profile, orthopaedists then create customised insoles by hand. The problem with this approach is that optimisations and adjustments take time. Another disadvantage is that the pressure-sensitive mats allow measurements only in a confined space, but not during workouts or outdoor activities.

Now an invention by a research team from ETH Zurich, Empa and EPFL could greatly improve things. The researchers used 3D printing to produce a customised insole with integrated pressure sensors that can measure the pressure on the sole of the foot directly in the shoe during various activities.

“You can tell from the pressure patterns detected whether someone is walking, running, climbing stairs, or even carrying a heavy load on their back – in which case the pressure shifts more to the heel,” explains co-project leader Gilberto Siqueira, Senior Assistant at Empa and at ETH Complex Materials Laboratory. This makes tedious mat tests a thing of the past. The invention was recently featured in the journal Scientific Reports.

One device, multiple inks
These insoles aren’t just easy to use, they’re also easy to make. They are produced in just one step – including the integrated sensors and conductors – using a single 3D printer, called an extruder.

For printing, the researchers use various inks developed specifically for this application. As the basis for the insole, the materials scientists use a mixture of silicone and cellulose nanoparticles.
Next, they print the conductors on this first layer using a conductive ink containing silver. They then print the sensors on the conductors in individual places using ink that contains carbon black. The sensors aren’t distributed at random: they are placed exactly where the foot sole pressure is greatest. To protect the sensors and conductors, the researchers coat them with another layer of silicone.

An initial difficulty was to achieve good adhesion between the different material layers. The researchers resolved this by treating the surface of the silicone layers with hot plasma.
As sensors for measuring normal and shear forces, they use piezo components, which convert mechanical pressure into electrical signals. In addition, the researchers have built an interface into the sole for reading out the generated data.

Running data soon to be read out wirelessly
Tests showed the researchers that the additively manufactured insole works well. “So with data analysis, we can actually identify different activities based on which sensors responded and how strong that response was,” Siqueira says.

At the moment, Siqueira and his colleagues still need a cable connection to read out the data; to this end, they have installed a contact on the side of the insole. One of the next development steps, he says, will be to create a wireless connection. “However, reading out the data hasn’t been the main focus of our work so far.”

In the future, 3D-printed insoles with integrated sensors could be used by athletes or in physiotherapy, for example to measure training or therapy progress. Based on such measurement data, training plans can then be adjusted and permanent shoe insoles with different hard and soft zones can be produced using 3D printing.

Although Siqueira believes there is strong market potential for their product, especially in elite sports, his team hasn’t yet taken any steps towards commercialisation.

Researchers from Empa, ETH Zurich and EPFL were involved in the development of the insole. EPFL researcher Danick Briand coordinated the project, and his group supplied the sensors, while the ETH and Empa researchers developed the inks and the printing platform. Also involved in the project were the Lausanne University Hospital (CHUV) and orthopaedics company Numo. The project was funded by the ETH Domain’s Advanced Manufacturing Strategic Focus Areas programme.

• General economic developments are dampening mood in composites industry
• Future expectations are optimistic
• Investment climate has remained stable
• Varying expectations for application industries
• Growth drivers have remained unchanged
• Composites Index is pointing in different directions

This is the 20th time that Composites Germany has identified the latest performance indicators for the fibre-reinforced plastics market. The survey covered all the member companies of the umbrella organisations of Composites Germany: AVK and Composites United, as well as the associated partner VDMA.  

General economic developments are dampening mood in composite industry
Like all industries, the composite industry has been affected by strong negative forces in recent years. The main challenges over the last few years have been the Covid pandemic, a shortage of semiconductors, supply chain problems and a sharp rise in the price of raw materials. Furthermore, there have been numerous isolated effects that added to the pressure on the industry.

The main challenges during the past year were primarily a steep increase in energy and fuel prices and the cost of logistics. In addition, the war in Ukraine put a further strain on supply chains that had already been weakened.

Overall, the stock market prices for both electricity and petroleum products are currently showing a clear downward trend. However, the significantly lower prices have not yet percolated from manufacturers and buyers to the end customer.

The aforementioned effects have further dampened the mood in the composites industry. The index assessing the current general business situation in Germany and Europe has dropped even further than before. However, the assessment of the global situation is somewhat more positive.

Despite this generally negative assessment of the current situation, companies are moving in a somewhat more positive direction in the assessment of their own business situations. The companies that were surveyed rated their own positions more positively than in the last survey.

Future expectations are optimistic
The expectations on future market developments are showing a very positive picture. After a significant drop in the last survey, the indicators for the general business situation are now displaying a clear upward trend again. Moreover, respondents were far more optimistic about their own companies’ future prospects.

Investment climate remaining stable
The investment climate has remained at a stable level. Nearly half of the companies surveyed are planning to employ new staff over the next six months. As before, about 70% of respondents are either considering or planning machine investments. Unlike in the previous survey, this value has remained almost unchanged.

Varying expectations for application industries
The composites market is highly heterogeneous in terms of both materials and applications. In the survey, respondents were asked to assess the market developments of different core areas. Expectations turned out to be extremely diverse.

The most important application segment for composites is the transport sector. The number of new registrations of passenger cars has been declining in recent years. This is where we can see OEMs moving away from volume models and opting for more profitable mid-range and premium segments. In this year’s survey, this shows itself in relatively cautious expectations for this segment.

The currently rather pessimistic outlook for the construction industry is leading companies to expect major slumps in this sector, in particular. The building sector, in particular, often reacts rather slowly to short-term economic fluctuations and has long been relatively robust towards the aforementioned crises. Now, however, it seems that this area, too, is being affected by negative influences.

The pessimistic outlook on the sports and leisure sector can be explained by a rather pessimistic view of consumer behaviour.

Expectations about future market developments, on the other hand, are significantly more positive than the figures presented here might suggest.

Growth drivers still stable
As before, the current survey shows Germany, Europe and Asia as the global regions expected to deliver the most important growth stimuli for the composites segment, with Europe playing a key role for many of the respondents.

Where materials are concerned, we are seeing a continuation of the ongoing paradigm shift. Whereas, in the first 13 surveys, respondents always believed that the composites segment would receive its prevailing growth stimuli from CRP, there is now an almost universal expectation that the most important stimuli will be coming from GRP or from all the materials.

Composites Index points in different directions
Despite the many negative influences that have occurred recently, composites appear to be in good shape for the future. Thanks to excellent market developments in 2021, they have almost reached their pre-pandemic level. The outlook for market developments in 2022 have not been finalised but are showing a less positive trend for last year.

Nevertheless, there are many indications to suggest that the generally positive development of the composite industry over the last few years is set to continue. In the medium term, structural changes in the transport sector will open up opportunities for composites to gain a new foothold in new applications. Major opportunities can be seen in areas of construction and infrastructure. Despite the rather weak market situation, these areas offer enormous opportunities for composites, due to their unique properties which predestine them for long-term use. The main assets of these materials are their durability, their almost maintenance-free use, their potential for use in lightweight construction and their positive impact on sustainability. Furthermore, one major growth driver is likely to be the wind industry, provided that it meets the politically self-imposed targets for the share of renewable energies in power consumption.

Overall, the Composites Index shows a restrained assessment of the current situation, whereas the assessment of the future situation is clearly positive. Respondents are apparently optimistic about the future, reflecting the assessment mentioned above: Composites have been used in industry and in serial production for several decades and, despite numerous challenges, they are set to provide immense potential for exploring new areas of application.

The next Composites Market Survey will be published in July 2023.

"Shared vision of a true circular economy for the textile industry"

US fashion group PVH has joined the fibre-to-fibre consortium founded by Carbios, On, Patagonia, PUMA and Salomon. The aim is to support the further development of Carbios' biorecycling process on an industrial scale, setting new global standards for textile recycling technologies. PVH owns brands such as Calvin Klein and Tommy Hilfiger. In the agreement signed by PVH Corp, the company commits to accelerating the textile industry's transition to a circular economy through its participation in the consortium.

Carbios is working with On, Patagonia, PUMA, PVH Corp. and Salomon to test and improve its bio-recycling technology on their products. The aim is to demonstrate that this process closes the fibre-to-fibre loop on an industrial scale, in line with sustainability commitments.

The two-year cooperation project will not only enable the biological recycling of polyester articles on an industrial scale, but also develop thorough sorting and disassembly technologies for complex textile waste. Existing members voted unanimously for PVH Corp. to join the consortium, saying the common goal is to support the development of viable solutions that address the fashion industry's contribution to climate change..

Carbios has developed a technology using highly selective enzymes that can recycle mixed feedstocks, reducing the laborious sorting required by current thermomechanical recycling processes. For textiles made from blended fibres, the patented enzyme acts only on the PET polyester contained within. This innovative process produces recycled PET (r-PET) that is equivalent in quality to virgin PET and can be used to produce new textile fibres.

Textile waste treatment and recycling
Globally, only 13% of textile waste is currently recycled, mainly for low-value applications such as upholstery, insulation or rags. The remaining 87% is destined for landfill or incineration. To work on improving textile recycling technologies, consortium members will supply feedstock in the form of clothing, underwear, footwear and sportswear. In 2023, a new PET textile waste facility will be commissioned at the Carbios demonstration plant, notably as part of the LIFE Cycle of PET project co-funded by the European Union.  This is in anticipation of future regulations, such as the separate collection of textile waste, which will be mandatory in Europe from 1 January 2025.

From fibre to fibre: circularity of textiles
Today, the textile industry relies largely on non-renewable resources to produce fibres and fabrics, partly turning to recycled PET bottles for recycled polyester fibres. However, this resource will become scarce as PET bottles are used exclusively for the production of new bottles in the food and beverage industry. In a circular economy, the materials used to produce textiles are obtained from recycled or renewable raw materials produced by regenerative processes. In addition to supplying raw materials for the demonstration plant, the consortium members also aim to produce new products from r-PET fibres using the company's biorecycling process.

"Partnering with Carbios and its consortium members demonstrates our continued commitment to incorporating more circular materials into our collections," said Esther Verburg, EVP, Sustainable Business and Innovation, Tommy Hilfiger Global and PVH Europe. "We are excited to support the development of Carbios' enzymatic recycling technology and to leverage new solutions that can help us drive fashion sustainably."

ESG aspects are most important to consumers when it comes to food and clothing. Young people in particular demand information and transparency: sustainability labels, certifications and reports ensure trust. For retailers and manufacturers, sustainability is becoming a must.

Under what conditions are the cows kept whose milk I drink? Does the manufacturer of my new T-shirt tolerate child labor? Does the retailer I trust deal fairly with employees and business partners? The majority of Germans ask themselves questions like these before making a purchasing decision. When shopping, 59 percent of consumers always or at least frequently pay attention to the ecological, economic or social sustainability of retailers and manufacturers. Among those under 35, the figure is even hugher with two-thirds, and among those over 55, one in two. These are the findings of a representative survey of 1,000 people in Germany commissioned by the auditing and consulting firm PwC Germany.

Sustainability is no longer a question of "if", but "how".
"Sustainability has become mainstream in recent years. For companies, paying attention to sustainability in their supply chains has already become a must," comments Dr. Christian Wulff. The Head of Retail and Consumer Goods at PwC Germany is convinced that companies will already have to give good reasons in the near future if they do not pay attention to the environment, social aspects and good corporate governance when producing a product. "The issue of sustainability is therefore no longer a question of whether, but of how," the retail expert continues.

Sustainability includes various aspects in the three areas of environment, social and sustainable governance (ESG). In the case of environmental sustainability, the focus is on issues relating to animal welfare - such as the conditions in which animals are kept or animal testing - and the use of recyclable materials. 40 percent of Germans would like to be informed about this before making a purchase. In the social sphere, the majority of respondents would like to know whether retailers and manufacturers comply with human rights (58 percent) - for example, whether they tolerate forced or child labor in their value chains. In terms of governance, one in two respondents would like to know about supply chains and be able to trace products before making a purchase.

Sustainability is particularly important for food
How closely consumers look at sustainability also depends on the product: For example, sustainability is particularly important to them when it comes to food. 81 percent of Germans pay attention to at least one of the three ESG criteria when buying food, i.e. environment, social issues or good corporate governance. But these criteria are also relevant when buying textiles: As many as 63 percent say they look at how sustainably the item was produced when buying clothing or shoes. While environmental aspects play the biggest role for food (62 percent), consumers are paying more attention to social aspects for clothing, shoes and accessories (52 percent).

Almost every second person has recently switched to sustainable products
The growing importance of ESG aspects in the purchasing behavior of German consumers is also evidenced by the shifts toward buying sustainable products. The trend toward sustainable products is clearest in the case of food: 45 percent of respondents state that they have consciously switched to more sustainable products within the past two years. By contrast, only 17 percent admit to switching (back) to less sustainable products, with one in three stating a lack of financial resources as the reason.

For just under half of those surveyed, a possible switch to more sustainable products would be supported by better availability in stationary retail. Legal regulations are also seen as helpful, both in terms of product labeling (38 percent) and for the production process (37 percent). More eye-catching product placement in stores would also help (37 percent).

Young people in particular demand transparency and education
Consumers' need for transparency in ESG matters is significant: According to the survey, almost three quarters of Germans obtain information about environmental sustainability issues at least occasionally. Two-thirds research aspects of social sustainability. A good half regularly find out about sustainable corporate governance.

Age has a major influence on how intensively people deal with the issue: While 80 percent of 16- to 24-year-olds find out about the environmental aspects of a product before buying it, only 59 percent of those over 65 do. "Younger people in particular are actively informing themselves and demanding transparency around ESG criteria," sums up Christian Wulff.

Consumers want information on packaging and online
To meet this need for information, the PwC expert advises manufacturers and retailers to provide detailed information about ESG aspects of products, especially online. "Keeping the associated, significantly increasing flood of data up to date at all times is increasingly becoming a challenge for companies that can only be solved by significant investments in new technologies."

Consumers agree on what companies can do to lend more credibility to their sustainability activities: A solid two-thirds consider recognized sustainability labels, certifications or independently audited sustainability reports to be suitable for credibly communicating activities in terms of ESG. "The results of our survey show that labels and independent certifications are very important in gaining the trust of customers. It is therefore worthwhile to have ESG measures confirmed by external organizations," says Christian Wulff.

Retailers and manufacturers should focus on transparency
"Manufacturers and retailers are faced with the task of ensuring a high level of transparency with regard to the sustainability of their products. This calls for honesty, but also creativity: In the case of fashion, for example, it is conceivable to trace the individual stages of the supply chain in detail and to show the costs incurred in the process. In this way, consumers can understand exactly how a price comes about," concludes Christian Wulff.

The Danish company Continuum Group ApS with its subsidiary companies in Denmark (Continuum Aps) and the UK (Continuum Composite Transformation (UK) Limited) wants to give end-of-life wind blades and composites a new purpose, preventing them going to waste. The goal is to reduce the amounts of CO₂ emitted to the atmosphere by the current waste streams, delivering a value to Europe’s Net Zero efforts.

Continuum states that it ensures all wind turbine blades are 100% recyclable and plans to build industrial scale recycling factories across Europe.

Net zero is the phrase on everyone’s lips, and as 2030 rapidly approaches we constantly hear updates about wind energy generating renewable energy that powers millions of European homes – but what happens when those turbine blades reach the end of their lifespan?

Currently the general answer is to put them into landfill or co-process them into cement, but neither is planet friendly. Many countries in Europe look to ban landfill from 2025, so this option is likely to be eliminated in the near future.

Continuum provides an alternative: When the end of their first life arrives, Continuum recycles them into new, high performing composite panels for the construction, and related industries. The vision of the Danes: Abandon the current landfilling, and drastically reduce CO₂ emitted during currently applied incineration & co-processing in cement factories by 100 million tons by 2050, via their mechanical composite recycling technology and their industrial scale factories.  

The technology is proven, patented, and ready to go, says Reinhard Kessing, co-founder and CTO of Continuum Group ApS, who has spent more than 20 years of research and development in this field, and advanced the reclamation of raw materials from wind blades and other composite products and transformation of these materials into new, high performing panel products.

By working with partners, Continuum’s cost-effective solution covers end-to-end logistics and processes. This spans from the collection of the end-of-life blades through to the reclamation of the pure clean raw materials and then the remanufacturing of all those materials into high value, highly performing, infinitely recyclable composite panels for the construction industry or the manufacture of many day-to-day products such as facades, industrial doors, and kitchen countertops. The panels are 92% recycled blade material and are said to outperform competing products.

Nicolas Derrien: Chief Executive Officer of Continuum Group ApS said: “We need solutions for the disposal of wind turbine blades in an environmentally friendly manner, we need it now, and we need it fast, and this is where Continuum comes in! As a society we are rightly focussed on renewable energy production, however the subject of what to do with wind turbine blades in the aftermath of that production has not been effectively addressed. We’re changing that, offering a recycling solution for the blades and a construction product that will outperform most other existing construction materials and be infinitely recyclable, and with the lowest carbon footprint in its class.”

Martin Dronfield, Chief Commercial Officer of Continuum Group ApS and Managing Director of Continuum Composite Transformation (UK) Ltd, adds: “We need wind energy operators & developers across Europe to take a step back and work with us to solve the bigger picture challenge. Continuum is offering them a service which won’t just give their business complete and sustainable circularity to their operations but help protect the planet in the process.“

Each Continuum factory in Europe will have the capacity to recycle a minimum of 36,000 tons of end-of-life turbine blades per year and feed the high value infinitely recyclable product back into the circular economy by 2024/25.

Due to an investment by Climentum Capital and a grant from the UK’s ‘Offshore Wind Growth Partnership’, Continuum are planning for the first of six factories in Esbjerg to be operational by the end of 2024 and for a second factory in the United Kingdom to follow on just behind it. After that they are looking to build another four in France, Germany, Spain, and Turkey by 2030.

As part of their own pledge to promote green behaviour, Continuum have designed their factories to be powered by only 100% green energy and to be zero carbon emitting environments; meaning no emissions to air, no waste fluids to ground, and no carbon fuel combustion.

Producing infection control clothing requires a lot of energy and uses lots of material resources. Fraunhofer researchers have now developed a technology which helps to save materials and energy when producing nonwovens. A digital twin controls key manufacturing process parameters on the basis of mathematical modeling. As well as improving mask manufacturing, the ProQuIV solution can also be used to optimize the production parameters for other applications involving these versatile technical textiles, enabling manufacturers to respond flexibly to customer requests and changes in the market.

Nonwoven infection control masks were being used in their millions even before the COVID-19 pandemic and are regarded as simple mass-produced items. Nevertheless, the manufacturing process used to make them needs to meet strict requirements regarding precision and reliability. According to DIN (the German Institute for Standardization), the nonwoven in the mask must filter out at least 94 percent of the aerosols in the case of the FFP-2 mask and 99 percent in the case of the FFP-3 version. At the same time, the mask must let enough air through to ensure that the wearer can still breathe properly. Many manufacturers are looking for ways to optimize the manufacturing process. Furthermore, production needs to be made more flexible so that companies are able to process and deliver versatile nonwovens for a wide range of different applications and sectors.

ProQuIV, the solution developed by the Fraunhofer Institute for Industrial Mathematics ITWM in Kaiserslautern, fulfills both of these aims. The abbreviation “ProQuIV” stands for “Production and Quality Optimization of Nonwoven Infection Control Clothing” (Produktions- und Qualitätsoptimierung von Infektionsschutzkleidung aus Vliesstoffen). The basic idea is that manufacturing process parameters are characterized with regard to their impact on the uniformity of the nonwoven, and this impact is then linked to properties of the end product; for example, a protective mask. This model chain links all relevant parameters to an image analysis and creates a digital twin of the production process. The digital twin enables real-time monitoring and automatic control of nonwoven manufacturing and thus makes it possible to harness potential for optimization.

Dr. Ralf Kirsch, who works in the Flow and Material Simulation department and heads up the Filtration and Separation team, explains: “With ProQuIV, the manufacturers need less material overall, and they save energy. And the quality of the end product is guaranteed at all times.”

Nonwoven manufacturing with heat and air flow
Nonwovens for filtration applications are manufactured in what is known as the
meltblown process. This involves melting down plastics such as polypropylene and forcing them through nozzles so they come out in the form of threads referred to as filaments. The filaments are picked up on two sides by air flows which carry them forward almost at the speed of sound and swirl them around before depositing them on a collection belt. This makes the filaments even thinner: By the end of the process, their thickness is in the micrometer or even submicrometer range. They are then cooled, and binding agents are added in order to create the nonwoven. The more effectively the temperature, air speed and belt speed are coordinated with each other, the more uniform the distribution of the fibers at the end and therefore the more homogeneous the material will appear when examined under a transmitted light microscope. Lighter and darker areas can thereby be identified — this is referred to by experts as cloudiness. The Fraunhofer team has developed a method to measure a cloudiness index on the basis of image data. The light areas have a low fiber volume ratio, which means that they are less dense and have a lower filtration rate. Darker areas have a higher fiber volume and therefore a higher filtration rate. On the other hand, the higher air flow resistance in these areas means that they filter a smaller proportion of the air that is breathed in. A larger proportion of the air flows through the more open areas which have a less effective filtration effect.

Production process with real-time control
In the case of ProQuIV, the transmitted light images from the microscope are used to calibrate the models prior to use. The experts analyze the current condition of the textile sample and use this information to draw conclusions about how to optimize the system — for example, by increasing the temperature, reducing the belt speed or adjusting the strength of the air flows. “One of the key aims of our research project was to link central parameters such as filtration rate, flow resistance and cloudiness of a material with each other and to use this basis to generate a method which models all of the variables in the production process mathematically,” says Kirsch. The digital twin monitors and controls the ongoing production process in real time. If the system deviates slightly from where it should be — for example, if the temperature is too high — the settings are corrected automatically within seconds.

Fast and efficient manufacturing
“This means that it is not necessary to interrupt production, take material samples and readjust the machines. Once the models have been calibrated, the manufacturer can be confident that the nonwoven coming off the belt complies with the specifications and quality standards,” explains Kirsch. ProQuIV makes production much more efficient — there is less material waste, and the energy consumption is also reduced. Another advantage is that it allows manufacturers to develop new nonwoven-based products quickly — all they have to do is change the target specifications in the modeling and adjust the parameters. This enables production companies to respond flexibly to customer requests or market trends.

This might sound logical but can be quite complex when it comes to development. The way that the values for filtration performance and flow resistance increase, for example, is not linear at all, and they are not proportional to the fiber volume ratio either. This means that doubling the filament density does not result in double the filtration performance and flow resistance — the relationship between the parameters is much more complex than that. “This is precisely why the mathematical modeling is so important. It helps us to understand the complex relationship between the individual process parameters,” says ITWM researcher Kirsch. The researchers are able to draw on their extensive expertise in simulation and modeling for this work.

More applications are possible
The next step for the Fraunhofer team is to reduce the breathing resistance of the nonwovens for the wearer without impairing the protective effect. This is made possible by electrically charging the fibers and employing a principle similar to that of a feather duster. The electric charge causes the textile fabric to attract the tiniest of particles which could otherwise slip through the pores. For this purpose, the strength of the electrostatic charge is integrated into the modeling as a parameter.

The Fraunhofer researchers’ plans for the application of this method extend far beyond masks and air filters. Their technology is generally applicable to the production of nonwovens — for example, it can also be used in materials for the filtration of liquids. Furthermore, ProQuIV methods can be used to optimize the manufacture of nonwovens used in sound-insulating applications.

Stylish sensors to wear 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.
 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.

The desire for a healthy lifestyle has triggered a trend towards self-tracking. Vital signs should be available at all times, for example to consistently measure training effects. At the same time, among the continuously growing group of people over 65, the desire to maintain performance into old age is stronger than ever. Preventive, health-maintaining measures must be monitored if they are to achieve the desired results. The search for measurement systems that reliably determine the corresponding health parameters is in full swing. In addition to the leisure sector, medicine needs suitable and reliable measurement systems that enable efficient and effective care for an increasing number of people in hospital and at home. After all, the increase in lifestyle diseases such as diabetes, cardiovascular problems or respiratory diseases is putting a strain on the healthcare system.

Researchers led by Simon Annaheim from Empa's Biomimetic Membranes and Textiles laboratory in St. Gallen are therefore developing sensors for monitoring health status, for example for a diagnostic belt based on flexible sensors with electrically conductive or light-conducting fibers. However, other, less technical properties can be decisive for the acceptance of continuous medical monitoring by patients. For example, the sensors must be comfortable to wear and easy to handle – and ideally also look good.

This aspect is addressed by a cooperation between the Textile and Design Alliance, or TaDA for short, in eastern Switzerland and Empa. The project showed how textile sensors can be integrated into garments. In addition to technical reliability and a high level of comfort, another focus was on the design of the garments. The interdisciplinary TaDA designer Laura Deschl worked electrically conductive fibers into a shirt that change their resistance depending on how much they are stretched. This allows the shirt to monitor how much the subjects' chest and abdomen rise and fall while they breathe, allowing conclusions to be drawn about breathing activity. Continuous monitoring of respiratory activity is of particular interest for patients during the recovery phase after surgery and for patients who are being treated with painkillers. Such a shirt could also be helpful for patients with breathing problems such as sleep apnea or asthma. Moreover, Deschl embroidered electrically conductive fibers from Empa into the shirt, which are needed to connect to the measuring device and were visually integrated into the shirt's design pattern.

The Textile and Design Alliance is a pilot program of the cultural promotion of the cantons of Appenzell Ausserrhoden, St.Gallen and Thurgau to promote cooperation between creative artists from all over the world and the textile industry. Through international calls for proposals, cultural workers from all disciplines are invited to spend three months working in the textile industry in eastern Switzerland. The TaDA network comprises 13 cooperation partners – textile companies, cultural, research and educational institutions – and thus offers the creative artists direct access to highly specialized know-how and technical means of production in order to work, research and experiment on their textile projects on site. This artistic creativity is in turn made available to the partners as innovative potential.

Flexible electronics have enabled the design of sensors, actuators, microfluidics and electronics on flexible, conformal and/or stretchable sublayers for wearable, implantable or ingestible applications. However, these devices have very different mechanical and biological properties when compared to human tissue and thus cannot be integrated with the human body.

A team of researchers at Texas A&M University has developed a new class of biomaterial inks that mimic native characteristics of highly conductive human tissue, much like skin, which are essential for the ink to be used in 3D printing.

This biomaterial ink leverages a new class of 2D nanomaterials known as molybdenum disulfide (MoS2). The thin-layered structure of MoS2 contains defect centers to make it chemically active and, combined with modified gelatin to obtain a flexible hydrogel, comparable to the structure of Jell-O.

“The impact of this work is far-reaching in 3D printing,” said Dr. Akhilesh Gaharwar, associate professor in the Department of Biomedical Engineering and Presidential Impact Fellow. “This newly designed hydrogel ink is highly biocompatible and electrically conductive, paving the way for the next generation of wearable and implantable bioelectronics.”¹ 

The ink has shear-thinning properties that decrease in viscosity as force increases, so it is solid inside the tube but flows more like a liquid when squeezed, similar to ketchup or toothpaste. The team incorporated these electrically conductive nanomaterials within a modified gelatin to make a hydrogel ink with characteristics that are essential for designing ink conducive to 3D printing.

“These 3D-printed devices are extremely elastomeric and can be compressed, bent or twisted without breaking,” said Kaivalya Deo, graduate student in the biomedical engineering department and lead author of the paper. “In addition, these devices are electronically active, enabling them to monitor dynamic human motion and paving the way for continuous motion monitoring.”

In order to 3D print the ink, researchers in the Gaharwar Laboratory designed a cost-effective, open-source, multi-head 3D bioprinter that is fully functional and customizable, running on open-source tools and freeware. This also allows any researcher to build 3D bioprinters tailored to fit their own research needs.

The electrically conductive 3D-printed hydrogel ink can create complex 3D circuits and is not limited to planar designs, allowing researchers to make customizable bioelectronics tailored to patient-specific requirements.

In utilizing these 3D printers, Deo was able to print electrically active and stretchable electronic devices. These devices demonstrate extraordinary strain-sensing capabilities and can be used for engineering customizable monitoring systems. This also opens up new possibilities for designing stretchable sensors with integrated microelectronic components.

One of the potential applications of the new ink is in 3D printing electronic tattoos for patients with Parkinson’s disease. Researchers envision that this printed e-tattoo can monitor a patient’s movement, including tremors.

This project is in collaboration with Dr. Anthony Guiseppi-Elie, vice president of academic affairs and workforce development at Tri-County Technical College in South Carolina, and Dr. Limei Tian, assistant professor of biomedical engineering at Texas A&M.
This study was funded by the National Institute of Biomedical Imaging and Bioengineering, the National Institute of Neurological Disorders and Stroke and the Texas A&M University President’s Excellence Fund. A provisional patent on this technology has been filed in association with the Texas A&M Engineering Experiment Station.

¹ This study was published in ACS Nano.

The Heimtextil Trend Preview 23/24 presented future-oriented design concepts and inspiration for the textile furnishing sector. With ‘Textiles Matter’, Heimtextil 2023 wants to set the benchmark for tomorrow’s forward-facing and sustainable textile furnishing. Hence, the focus is on circularity. Marta Giralt Dunjó of futures research agency FranklinTill (Great Britain) presented the design prognoses for 23/24. At the coming Heimtextil in Frankfurt am Main from 10 to 13 January 2023, the presentations of new products will generate stimulating impulses in the Trend Space.

The Heimtextil Trend Council – consisting of FranklinTill Studio (London), Stijlinstituut Amsterdam and Denmark’s SPOTT Trends & Business agency – offers insights into the future of the national and international market. The focus is more than ever before on sustainability and the circular economy, the main factors in setting the trends for the season 23/24.

Textiles Matter: bear responsibility
Textiles are an integral part of modern life. The material applications and the manufacturing processes are no less multifarious than user expectations. And this represents a great challenge for the international textile industry, which obtains its raw materials from a broad spectrum of sources and uses numerous processes to make a huge variety of products. This offers a great potential for the sustainable development of the textile industry in the future. The Heimtextil Trends show ways in which this potential can be utilized and sustainable developments promoted. Under the motto ‘Textiles Matter’, visitors can explore concepts for increased circularity, which will generate new impulses for the sustainable market of the future.

"Considering the state of environmental emergency we are currently living through, the textile industry has a responsibility to examine its processes, and change for the better. That is why for this edition of the Heimtextil Trends we are taking a material’s first approach, and focusing on the sourcing, design, and sustainability of materials. Textiles Matter showcases the potential of circularity and celebrates design initiatives that are beautiful, relevant and importantly sustainable”, explains Marta Giralt Dunjó of FranklinTill.

Change via circularity
The Trend Space at the coming Heimtextil 2023 will revolve around ideas and solutions for circularity in the textile sector. How can textiles be produced in a sustainable way? What recycling options are there? What does the optimum recycling of textile products look like? Within the framework of the circular economy, materials are continuously reused. On the one hand, this reduces the need for new raw materials and, on the other hand, cuts the amount of waste generated. In the technical cycle, inorganic materials, such as nylon, polyester, plastic and metal, can be recycled with no loss of quality. In the biological cycle, organic materials, such as linen and bast fibres, are returned to nature at the end of their useful life. This is the basis of the four trend themes: ‘Make and Remake’, ‘Continuous’, ‘From Earth’ and ‘Nature Engineered’.

Make and Remake
Pre-used materials, deadstock and remnant textiles are given a new lease of life with the focus shifting to the aesthetics of repair and taking the form of a specific design element of the recycled product. Bright and joyful colours and techniques, such as overprinting, overdyeing, bricolage, collage and patchwork, result in new and creative products. Layered colour patterns and graphics lead to bold and maximalist, yet conscious, designs.

Continuous
The Continuous trend theme describes closed-loop systems in which materials are recycled into new, waste-free products again and again. Putative waste materials are separated out and reprocessed as new fibres, composites and textiles. Thus, synthetic and cellulose yarns can be produced zero-waste. Thanks to technically advanced reclamation processes, the materials retain their original quality and aesthetic. Practicality, essentialism and longevity determine the design of Continuous products.

From Earth
This theme focuses on the natural world and harmony with the nature of organic materials. Natural colours communicate warmth and softness. Imperfect textures, signs of wear and irregularities create ecological and earth-born aesthetics. Earthen and botanic shades, natural variation and tactile richness dominate the From Earth segment. Unrefined and raw surfaces, unbleached textiles and natural dyes celebrate materials in their original states.

Nature Engineered
Nature Engineered uses mechanical means to elevate and perfect organic materials, such as bast fibres, hemp, linen and nettles. Cutting-edge techniques process natural textiles into sophisticated and smart products. Combined with shades of beige and brown, clean lines and shapes are the distinguishing features of this theme.

Swansea University academics have pioneered a process which converts the carbon found in discarded facemasks to create high-quality single-walled carbon nanotubes (CNT) which were then used to make Ethernet cable with broadband quality.
 
The study, which has been published in Carbon Letters, outlines how this new green chemistry could be used to upcycle materials which would otherwise be thrown away and transform them into high value materials with real-world applications. The CNTs produced by this technique have the potential not only to be used in Ethernet cables, but also in the production of lightweight batteries used in electric cars and drones.

Professor Alvin Orbaek White, of Swansea University’s Energy Safety Research Institute (ESRI):
“Single-use facemasks are a real travesty for the recycling system as they create vast amounts of plastic waste - much of it ending up in our oceans. During the study, we established that the carbon inside the facemask can be used as a pretty good feedstock to make high-quality materials like CNTs.

“CNTs are highly sought-after because they have preferential physical properties and tend to be much more costly on an industrial scale. So, through this study, we demonstrated that we could make very high value materials by processing the CNTs from what are, essentially, worthless waste facemasks.”

The team also studied the energy costs involved in using this process and concluded that the technique was green not only in levels of resource consumption but also in the product value generation as opposed to waste creation. Also, the Ethernet cable produced using the CNTs was good quality and adhered to Category 5 transmission speeds while easily exceeding the benchmarks set for broadband internet in most countries, including the UK.

Professor Orbaek White said:
“Using CNT films in batteries instead of metal films has a lower impact on the environment as the use of carbon offsets the need for mining and extraction activities. This is a crucial piece of work as it contributes to not only a circular economy but is also scalable and is viable for industrial processing and has green chemistry at its core.”